72291971 has 2 divisors, whose sum is σ = 72291972. Its totient is φ = 72291970.

The previous prime is 72291959. The next prime is 72291997. The reversal of 72291971 is 17919227.

It is a weak prime.

It is an emirp because it is prime and its reverse (17919227) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 72291971 - 2¹⁰ = 72290947 is a prime.

It is a super-2 number, since 2×72291971² = 10452258142129682, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (72291931) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36145985 + 36145986.

It is an arithmetic number, because the mean of its divisors is an integer number (36145986).

Almost surely, 2^72291971 is an apocalyptic number.

72291971 is a deficient number, since it is larger than the sum of its proper divisors (1).

72291971 is an equidigital number, since it uses as much as digits as its factorization.

72291971 is an evil number, because the sum of its binary digits is even.

The product of its digits is 15876, while the sum is 38.

The square root of 72291971 is about 8502.4685239053. The cubic root of 72291971 is about 416.5783433767.

The spelling of 72291971 in words is "seventy-two million, two hundred ninety-one thousand, nine hundred seventy-one".